International Patent Publication No. WO2005/097339 discloses a conventional electrostatically atomizing device for generating charged minute particles of nanometer size (nanometer-size mist). In the device, a high voltage is applied across an emitter electrode, supplied with water, and an opposed electrode, to induce Rayleigh breakup of the water held on the emitter electrode, thereby atomizing the water. The charged minute water particles thus obtained, long-lived and containing radicals, can be diffused into a space in large amounts. These water particles can thus act effectively on malodorous components adhered to indoor walls, clothing, or curtains, to deodorize the same. The device comprises cooling means for cooling the emitter electrode and forming thereby condensed water on the emitter electrode, out of air moisture; and a controller for detecting a discharge current flowing between the electrodes and for controlling the cooling means in such a way so as to maintain the discharge current at a predetermined value, while keeping the discharge voltage applied between the emitter electrode and the opposed electrode at a predetermined value.
However, continued generation of nanometer-size charged minute particles on the basis of a control scheme whereby the discharge voltage is kept at a predetermined value, while supplying a predetermined amount of a liquid to the emitter electrode by controlling the cooling temperature of the emitter electrode in such a manner that the discharge current takes on a predetermined value, is problematic in that there elapses a long response time between detection of the discharge current and generation of condensed water through cooling of the emitter electrode.